Environmental Toxicology - Quantifying contaminant impacts ...cfink/ES 10/finkelstein.pdf ·...

Environmental Toxicology -

Quantifying contaminant impacts

& identifying solutions

ES 10 Spring 2016 Myra Finkelstein (myraf@ucsc.edu)

Associate Adjunct Professor

Microbiology & Environmental Toxicology

What are the effects of environmental contamination on individuals and populations?

Classic toxicology:

Establish relationship: Dose Response

Dose

Re

sp

on

se

(ce

ll d

ea

th)

Contaminant effects in a wild species

(as opposed to in a dish of cells in a lab)

food

predation competition

survival

reproduction

Not easily defined!

Challenging to assess contaminant-induced effects in wild populations

Effects are typically really bad before we can detect them!

cell function

Most contaminant effects not overt

overt

Contaminant effects system

function

Egg shell thinning –

zero reproductive success

1947-1971: 110 tons of DDT

So. CA Bight

DDT DDE

biota

DDT banned

California Brown Pelicans

endangered species

DDE & Brown Pelicans

X

Smallest of North Pacific albatross

- wing span ~ 2 m

- weigh ~ 2.7 kg

Long-lived ~ 60 yrs, start breeding ~ 8yrs

Low reproduction – one chick per year

Naturally low adult mortality

Laysan albatross

(Phoebastria immutabilis)

Wide-ranging

- good indicators of

pelagic systems

Accessible for studying

- tied to land to breed

Finkelstein et al., Ecol. Apps. (2006)

Pelagic predator

Laysan albatross

1900’s: Feather harvesting reduced populations by >90%

Laysan albatross

~ 400,000 pairs

~ 70% of global population

•Former

military base

•U.S. Wildlife

Refuge

Study Site: Midway Atoll

*

Quantify impact

Extrapolate to populations

Identify solutions

?

Quantify impact

Extrapolate to populations

Identify solutions

?

Midway Atoll: 70% of breeders;

former military base

Lead contamination a problem? Highly toxic

– Nervous

– Blood

– Immune

– Renal

– Reproductive

Laysan chicks: High lead exposure

0

50

100

150

200

250

300

350

400

450

near buildings n=21

reference n=15

blo

od lea

d (

µg/d

L)

severe morbidity

clinical treatment

> 90% of chicks near bldgs. likely

lethally exposed to lead

Lead exposure causing lethal lead effects

droopwing

0

50

100

150

200

250

300

350

400

450

near buildings n=21

reference n=15

blo

od lea

d (

µg/d

L)

Quantify impact

Extrapolate to populations

Identify solutions

survival

reproduction lead

bycatch

Population Viability Analysis:

Mathematical models to predict likely future status of a

population

Vital rates:

- survivorship of individuals by age

- number of young per female

Key impacts:

- lead effects on chick survival:

7% (~10,000 chicks/year)

- bycatch effects on adult survival

1 to 3%

Translate individual impacts to populations with

Population Viability Analysis (PVA)

Laysan albatross populations declining

on Midway Atoll

440000

640000

840000

1040000

1240000

0 20 40 60 80 100

years into future

popula

tion s

ize

current conditions

Eliminating lead reduces population decline

440000

640000

840000

1040000

1240000

0 20 40 60 80 100

years into future

popula

tion s

ize

no lead deaths

current conditions

Need to reduce bycatch for stable growth

Finkelstein et al., Anim. Cons. (2010)

440000

640000

840000

1040000

1240000

0 20 40 60 80 100

years into future

popula

tion s

ize

no lead deaths

increase adult

survivorship by 1%

current conditions

(plastic?)

Plastic disposal from ships/offshore transport

Ingested by wildlife

Accumulation at

convergence zones

Quantify impact

Extrapolate to populations

Identify solutions

survival

reproduction lead

bycatch

Identify solutions for reducing lead-related

mortality:

1. Identify exposure source

2. Eliminate/reduce exposure

source

Source of lead exposure: Isotopic analysis

4 stable lead isotopes

Lead signatures in organism

reflect lead signatures in source

- Trace metal clean techniques

- Highly sensitive measurements

Concentrated nitric acid

1

10

100

1000

chicks near buildings

n=21

chicks reference

n=15

adults

n=10

- Diet-derived source – NO – adults low

- Widespread soil contamination – UNLIKELY– reference low

- Lead-based paint on buildings - POSSIBLE

lo

g b

loo

d le

ad

(µ

g/d

L)

Identify plausible source(s) of lead exposure

blood

0.80 0.82 0.84 0.86 0.88 0.90 0.92 2.02

2.04

2.06

2.08

2.10

2.12

2.14

2.16

207Pb/206Pb

20

8P

b/2

06P

b

Lead-based paint source of poisoning

paint

Finkelstein et al., ES&T (2003)

Chick 4

Chick 3

Chick 2 Chick 1

Increase adult survivorship: Reduce fisheries bycatch

• international regulations

• complex political/social issues

Solutions to increase population growth

Eliminate lead poisoning: ~190,000 more birds in

50 years Finkelstein et al., Anim. Cons. (2010)

Increase chick survivorship: Remediate lead paint

• technology exists

• straightforward

Published research: “Assessment of demographic risk factors and management priorities: impacts

on juveniles substantially affect population viability of a long-lived seabird”

Finkelstein et al., Animal Conservation, 2010 13: 148–156

Share research results to inform decisions

June 2010:

lead paint clean-up authorized

Paint clean-up will eliminate lead poisoning of

Laysan albatross chicks

North America’s largest bird

- wing span ~ 3 m

- weigh ~ 9 kg

Long-lived ~70 yrs, start breeding ~ 6yrs

Low reproduction – one chick per year

Naturally low adult mortality

California condor

(Gymnogyps californianus)

Effective scavengers!

California condor decline

Map courtesy of M. Johnson

data adapted from Snyder and Snyder (1989)

• ~600 birds end 1800’s

• 22 condors in 1982 End 1800’s

1982

California condor: One of world’s rarest birds

• 1980s - breeding program

• 1987 all condors in captivity

• 1992 first release of captive- reared birds

United States - Federal protection since 1970’s

IUCN - Critically Endangered since 1994

USFWS 2013

Pinnacles National Park

Ventana Wilderness

Bitter Creek

Vermillion Cliffs

Sierra de San Pedro Martir

Wild: - California, USA: 155

- Baja California, MX: 33

- Arizona, USA: 80

California condor

December 31st 2014

Total population: 435

(zoos & “wild”)

0

20

40

60

80

100

120

140

160

180

200

19

94

19

96

19

98

20

00

20

02

20

04

20

06

20

08

20

10

20

12

Wild population increase due to captive releases N

um

be

r o

f b

ird

s

Wild-

fledges

Dead or

removed

Captive-

reared

releases

More die than born = population not sustainable

• 1970’s: documentation condors

have high lead

• 1980’s: first lead-related condor

death identified

Quantify impact

Translate to populations

Identify solutions

?

Monitored on near daily basis • blood lead checked ~2x per year

• odd behavior – trapped to assess lead

• blood lead ≥45 µg/dL – clinical treatment

0

10

20

30

40

50

60

70

80

90

100

Year

1998 2000 2002 2004 2006 2008 2010 2012

Perc

ent

lead p

ois

oned

~20% of condors tested per year

need clinical treatment

~60% of wild birds lead poisoned

Finkelstein et al. 2012 n = 987 independent blood samples

Lead poisoning: # 1 mortality factor for

juvenile & adult free-flying condors

Rideout et al., J. Wildl. Dis. (2012)

Quantify impact

Extrapolate to populations

Identify solutions

survival

reproduction lead

Condor performance over past 20 yrs

• annual survivorship of individuals

• number of fledged young/female

Three scenarios - no future releases

• continued management for lead

• cessation of management for lead poisoning

• no lead deaths

Translate individual impacts to populations with

Population Viability Analysis (PVA)

0 5 10 15 20 0

20

40

60

80

100

120

140

Lead preventing condor recovery

lead

management

no lead

management

no lead deaths

Finkelstein et al., PNAS. (2012) years into future

# f

ree

-fly

ing b

irds in C

alif

orn

ia

lead

Quantify impact

Extrapolate to populations

Identify solutions

survival

reproduction

1. Identify exposure source

2. Eliminate/reduce exposure

source

Identify solutions for reducing lead-related

mortality:

Condors ingest spent lead ammunition

Finkelstein et al. (2012)

0.76

0.78

0.8

0.82

0.84

0.86

0.88

0.9

0.92

303 306 318 401 400 452

Condor ID

lea

d r

ati

o (

20

7P

b/2

06P

b)

blood lead item

Source of lead exposure:

Isotopic analysis

Ammunition principal

source of lead to condors

1. Reduce use of lead ammunition

2. Reduce reliance on lead-shot carcasses

Solutions to increase population growth

Reduce exposure to lead-based ammunition

On California beaches each year:

• ~100 cetaceans

• ~2,000 pinnipeds

Lead-shot carcasses - terrestrial

Condors on coast: Lower lead

poisoning risk

0

0.1

0.2

0.3

0.4

<50% 50-74% >=75%

% time on observed on coast (n=63 birds)

pro

bab

ility

lea

d p

ois

on

ed

(n

=5

23

blo

od

sa

mp

les)

Condor:

Top marine scavenger

Terrestrial

Pollution

(DDE)

grass

deer

condor

zooplankton

fish

marine mammals

Marine

phytoplankton

condor

www.gotmercury.org

0

500

1000

1500

2000

2500

3000

coastal n=22

inland n=8

DD

E p

lasm

a (

µg/d

L)

Coastal condors: Higher DDE

peregrine falcon

egg shell thinning

bald eagle egg shell thinning

prairie falcon egg shell thinning

Next steps: Quantify impacts of lead and DDE

0 5 10 15 20 0

20

40

60

80

100

120

140

lead

management

no lead

management

no lead deaths

years into future

Fre

e-f

lyin

g p

opula

tion s

ize in C

alif

orn

ia

DDE ?

Solutions to increase population growth

Reduce exposure to lead-based ammunition

DDE?

1. Reduce use of lead ammunition

2. Reduce reliance on lead-shot carcasses

Share research results to inform decisions

Oct. 2013: law to require non-lead ammunition for

hunting throughout entire state of California

Use of non-lead ammunition: Prevent lead poisoning of condors

and promote species recovery

Research supported by US Fish and Wildlife Service

National Park Service

Montrose Settlements Restoration Fund

Western National Parks Association

David H. Smith Postdoctoral Fellowship

Switzer Environmental Leadership Grant

Switzer Environmental Fellowship

EPA STAR Graduate Fellowship

ARCS Scholarship Collaborators Don Smith (UCSC), Dan Doak (CU-Boulder),

Vickie Bakker (MSU), Carolyn Kurle (UCSD),

David Anderson (WFU), Joseph Brandt

(USFWS), Joe Burnett (VWS), Don Croll

(UCSC), Daniel George (NPS), Roberto

Gwiazda (MBARI), Brad Keitt (IC), John

Klavitter (USFWS), Paul Sievert (UMass),

Bernie Tershy (UCSC), Gerald Winegrad (ABC)

Special thanks USFWS, Midway Atoll National

Wildlife Refuge, Rob Franks, Breck

Tyler, Thierry Work , Los Angeles

Zoo, Pinnacles National Pak,

Ventana Wildlife Society

Undergraduate/Graduate students Molly Church, Mary Goldman, Gayle

Kouklis, Zeka Kuspa, Lauren Lee,

Melinda Nakagawa, Mara Nydes

Photo credits Joe Burnett, Mike Clark, Gavin Emmons,

Daniel George, Bill Henry, Pinnacles

National Park, Graham Robertson, Don

Smith, Stuart Thorton, Breck Tyler